Science and Technology › Energy technology
Wind, hydro and other renewables
Wind, hydro and the other renewables: onshore and offshore wind, large and small hydropower and the risks of building in the Himalaya, geothermal energy, and energy from tides, waves and ocean heat. It serves GS3 answers on energy and infrastructure.
Geothermal energy
India has drilled its first geothermal wells but generates nothing from them yet: the two at Puga Valley in Ladakh are there to assess a reservoir, not to sell power. The sector has had a national policy since 2025 and no plant to show for it.
Also drawn on, not yet tied to one subject: PIB, 4 Sep 2026: Geothermal Energy: A New Chapter in India's Clean Energy Journey (PIB Backgrounder) (opens in a new tab)
4 Sep 2026 · Prelims and Mains
Puga Valley geothermal wells
Geothermal energy taps heat that is already in the ground, so a well is an exploration job before it is a power project. The ONGC Energy Centre, set up by the Oil and Natural Gas Corporation, commissioned India's first two at Puga Valley in Ladakh, drilled in July 2026.
Heat
Radioactive decay of uranium, thorium and potassium, and heat left from the Earth's formation
Reservoir
Where faults let hot material rise, hot water and steam collect in permeable rock
Power
Wells bring it up to drive a turbine, with no fuel burnt
- They are assessment wells: they will evaluate the reservoir for India's first 1 MW demonstration geothermal power project.
- Unlike solar and wind, geothermal power is available round the clock.
4 Sep 2026 · Prelims and Mains
National Policy on Geothermal Energy
The policy is broader than power generation, and most of what it covers never reaches a turbine.
- Its nodal ministry is the Ministry of New and Renewable Energy.
- It covers exploration, direct use, ground source heat pumps and the repurposing of abandoned oil and gas wells.
Hydropower
India is building small run of river hydropower, which a new central scheme is meant to unlock, while the large projects in the Himalaya are argued over for where they sit, after Nepal's August flood destroyed two and damaged at least thirteen under construction.
Also drawn on, not yet tied to one subject: PIB, 10 Sep 2026: Small Hydro Power has a distinctive role in India's clean energy transition: Shri Shripad Yesso Naik (opens in a new tab)
10 Sep 2026 · Prelims and Mains
Small hydro power
A stream that falls steeply enough will turn a turbine with no reservoir behind it, which is the whole case for building small.
Why small hydro
- Run of river designs need relatively little land
- No large scale submergence or displacement
- Power close to where it is used, in remote terrain
The barriers
- Long lead times
- Delays in forest, environment and right of way clearances
- Hard to finance, so the Indian Renewable Energy Development Agency was urged to bring in long term patient capital
- Small hydro in India means a project of up to 25 MW, usually run of river, using a stream's natural fall rather than a large reservoir.
10 Sep 2026 · Prelims and Mains
Small Hydro Power Development Scheme
The scheme now proposed builds no plant; it pays for the survey work that has to exist before anyone will lend against one.
21 GWAssessed small hydro potential, at more than 7,100 sites
5.2 GWHarnessed so far
200Projects to get Detailed Project Reports
- A Small Hydro Power Development Scheme was proposed for 2026-27 to 2030-31, at ₹2,584.60 crore for about 1,500 MW.
- It pays States to prepare Detailed Project Reports, so the pipeline exists before the money does.
7 Sep 2026 · Prelims and Mains
Hydropower in the Himalaya
The mountains hold most of the fall a turbine wants and most of the hazard a project cannot survive.
- The Himalaya is young, steep and seismically active, so a glacial lake burst or a landslide reaches a project built in the valley below it.
- Nepal's 26 August flood destroyed two hydropower projects and damaged at least thirteen under construction, and the damage was blamed less on the trigger than on where the projects sat.
- A cumulative impact assessment weighs every project on a river basin together, rather than clearing each one on its own.
- Neither Nepal nor India assesses Himalayan projects basin by basin, so each clearance ignores what the others have already done.
- The World Commission on Dams reported in 2000 that a dam's costs fall on the people nearest it while its benefits travel, which is the argument still being had.
See also: Gram sabha consent for forest clearance
Frontline, 7 Sep 2026: A warning in the waters (opens in a new tab) · Frontline, 7 Sep 2026: Every disaster also presents an opportunity to learn: Himanshu Thakkar (opens in a new tab) · The Indian Express, 30 Aug 2026: Nepal floods: The red flags in dam-building in the Himalayas (opens in a new tab) · The Indian Express, 1 Sep 2026: Express in Nepal: How hydropower firm is planning search for missing staff (opens in a new tab)
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